name: duk_opt_context

proto: |
  duk_context *duk_opt_context(duk_context *ctx, duk_idx_t idx, duk_context *def_value);

stack: |
  [ ... val! ... ]

summary: |
  <p>Get a context pointer for a Duktape thread at <code>idx</code>.  If the
  value is <code>undefined</code> or the index is invalid, <code>def_value</code>
  default value is returned.  In other cases (<code>null</code> or non-matching
  type) throws an error.</p>

  <div include="default-pointer-validity.html" />

example: |
  duk_context *target_ctx;

  target_ctx = duk_opt_context(ctx, 2, default_ctx);

tags:
  - stack
  - borrowed

introduced: 2.1.0